Mr Mitchell's defence of his position came after he was criticised by the mother of a victim of a murderer whose life the former Fine Gael TD appealed be spared.

The self-confessed pro-life advocate and Dublin MEP admitted he had written a "number" of letters that pleaded for leniency towards those sentenced to death.

"I have written to governors to ask that people not be injected to death, hanged to death, shot to death or stoned to death.

"The death penalty is barbaric and I make no apologies whatsoever for campaigning against it," he said.

The Fine Gael MEP hand- delivered a letter to the US embassy in Dublin appealing for the life of murderer Louis Truesdale to be spared in 1998.

Truesdale was sentenced to death for the shooting and rape of 18-year-old American girl Rebecca Eudy on April 4, 1980, after he abducted her from a car park.

The victim's mother, Evelyn, said she was appalled to hear Mr Mitchell was running as a presidential candidate in Ireland.

Mr Mitchell also wrote to the former governor of Florida, Jeb Bush, seeking clemency for double murderer Paul Hill, who killed a doctor who carried out abortions and his bodyguard in 1994.

Neither this letter nor any subsequent letters he penned to US governors pleading for the lives of death-row prisoners to be spared have been released to the public.

Mr Mitchell said he could not release the letters into the public domain as he "did not have them".

Earlier this month, Senator David Norris withdrew from the presidential race after controversy followed revelations that he sought clemency from an Israeli court, on Seanad headed paper, for his former partner Ezra Yitzhak Nawi on his conviction for the statutory rape of a 15-year-old Palestinian boy in 1997.

Incensed

Mr Mitchell, who became quite incensed during the interview yesterday, said he did not know exactly how many letters he had written pleading for the lives of those sentenced to death, but admitted there were "a number".

In an apparent effort to drag other presidential hopefuls into the controversy, he demanded the other candidates set out their position on the death penalty.

While canvassing in Greystones, Co Wicklow, Mr Mitchell questioned why he was being asked about his beliefs while other candidates were not.

He said people should be proud to have a candidate with the "courage and the moral fibre" to take a stand against the death penalty.